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Present: Bolko Beutner Lars Froehlich @Marc Guetg Raimund Kammering @Torsten Limberg Sascha Meykopff Matthias Scholz @Sergey TominJosef Wilgen

Linear undulator taper

Svitozar reminded us that we could calculate the necessary linear taper for our undulators due to spontaneous radiation and resistive wall wakefields. Bolko is going to gather the necessary formulas and parameters and will provide them to Olaf. In a first step, it should be sufficient to display the calculated value alongside the user-defined taper parameters.

LLRF energy gain server/energy manager

Bolko has observed that the new fudge factors are not implemented optimally – they scale the total energy, not the energy gain of the individual stations, and therefore become invalid when the energy distribution changes. There is also a difference between the setpoint of the energy manager and the readback from the LLRF that should be addressed. Lars and Olaf are going to investigate possible improvements.

Magnet Energizer Server

We discuss if we have enough use cases for a server version of the magnet energizer. Most use cases concern scripts that can just as well use the energy profile server and the magnet ML server directly, so we decide not to pursue the server project for now.

LLRF Flat tops

We discuss what might be needed to make the handling of RF flat-tops more transparent:

  • A property calculating the transition time needed for the current settings of amplitude and phase of adjacent flat-tops (e.g. 80 µs)
  • The same value as a fraction relative to the current setting of the transition time (e.g. 40% if the current transition time is 200 µs)
  • The remaining headroom in terms of amplitude, phase, I, Q, chirp, etc. (to be discussed)

There is clearly a need for a meeting with some LLRF experts to define this better. Torsten is going to organize it.

Action items

  • Gather formulas and parameters for linear taper calculation  Bolko Beutner
  • Organize meeting on RF flat-tops @Torsten Limberg